Safety approach

A diversity of failure mechanisms need to be analysed during the design phase of a reclamation project in order to guarantee sufficient safety. One of the main failure modes to be checked is the Ultimate Limit State (ULS). The purpose of ULS calculations is to determine the minimum safety factor in case the available strength is fully mobilised. 

The different failure modes discussed in this chapter all relate to the Ultimate Limit State. When checking the safety, the maximum available strength of the soil to be mobilised is defined. The corresponding safety factor is then calculated for the actual condition. Generally, the required value of the safety factor reflects both the uncertainty with respect to the soil parameters and loads as well as the extent of the consequences should a failure occur. 

Two safety approaches exist which are briefly discussed in this section. In principle, one of the following safety approaches can be followed  

In the partial safety approach the uncertainties of all parameters are taken into account this principle is not only used for soil mechanics but also for other disciplines. The first step is to define characteristic values for the soil parameters. This already is a difficult exercise and requires extensive testing and analysis of the soil in geoteehnically homogeneous layers. 

The eharacteristic value is a safe estimation of the average value over a large homogeneous soil zone or the 5% lower bound fractile of all values measured. The first assumption is valid when the failure mode studied mobilises a large soil volume, while the second assumption applies for small foundation elements only. 

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The approaches described in this chapter can be regarded as complementary rather than competing methodologies. They all have a part to play in an integrated approach to the management of human error to reduce accidents in the CPI. Having said this, we will place rather more emphasis on approaches other than the traditional safety approach in this book. 

Three approaches to risk analysis will be presented here for the available chlorpyrifos exposure data, namely (1) the single point, margin of safety approach (2) probability analysis and (3) Monte Carlo simulation. 

MOE (Margin of Exposure) approach is formally similar to the MOS (Margin of Safety) approach for threshold effects (see Section 8.3.3 for MOS approach). 

Ionizing radiation is divided into alpha and beta particles and gamma rays. Each has its unique characteristics, which require different safety approaches. In general, the more radiation exposure a person receives, the greater the likelihood of cancer. 

H, Visser R (2000) Work in OECD on Chemical Safety Approaches for human risk assessment. Industrial Health 38 109-119... 

Although firms sometimes do anticipate accidents and try to avoid them, the expenditures for adequate prevention have not been, and are not likely to be, invested without the right incentives. To the extent that the firm knows that the costs of maintenance and the inflexibility of traditional safety approaches are greater than using more reliable, inherently safer approaches, the firm may respond by changing its technology. 

ASSESSMENT OF RISKS TO HUMANS EXPOSED TO PESTICIDES 2 The Four Steps in Risk Assessment 2 Hazard Identification 2 Dose-Response Assessment 3 Margin of Safety Approach 3 Quantitative Risk Assessment 3 Exposure Assessment 4 Risk Characterization 4 RISK MANAGEMENT 5 ADVANCES IN DATA INTERPRETATION 5 Probabilistic Approaches 5 Recognition of the Tier Approach 5 Aggregate Exposure 6 Cumulative Exposure 6 Impact of New Scientific Advances 7 Post-Registration Monitoring 7 HARMONIZATION OF REGULATORY APPROACHES SUMMARY 9... 

The importance of accurate and relevant exposure data to the reliability of the risk assessment derived from both the margin of safety approach and the quantitative cancer risk assessment cannot be over-emphasized. 

Accidents in industry occur for many reasons. A few of which can be attributed to mechanical failure, operational error (human error), and process upset, and design error. In order to understand tlie root cause of an accident, system safety approaches have been put to use. 

A. Bassi et al.. Massive H2 production with nuclear heating, safety approach for coupling A VHTR with an Iodine Sulfur process cycle, ICHS, Pisa, September 8-10, 2005. 

The viral safety approach for mammalian cell culture-derived biopharmaceuticals... 

Fig, 8-1 Safety approach for handling hydrogen in the industries, from [10]... 

The large-scale industrial application of hydrogen has led to a safety concept with a scale of safety measures aimed at minimizing risks by preventive safety measures and by mitigation measures. A basic safety approach that can be applied to hydrogen energy technologies is outlined in Fig. 8-1. Some examples are [45]... 

Safety approaches based on systems theory consider accidents as arising from the interactions among system components and usually do not specify single causal variables or factors [112]. Whereas industrial (occupational) safety models and event chain models focus on unsafe acts or conditions, classic system safety models instead look at what went wrong with the system s operation or organization to allow the accident to take place. 

Ota, Daniel Shuichiro. Assuring Safety in High-Speed Magnetically Levitated (Maglev) Systems The Need for a System Safety Approach. Master s thesis, MIT, May 2008. 

As the experts make substantive changes in what they prescribe, will reflection after the passage of time result in the conclusion that what they proposed in the beginning was just another fad The critics are right when they say that behavior modification and psychology of safety approaches inappropriately focus on employee performance, rather than on management s responsibility to provide a safe operating system. Also, whether the subject is productivity, cost efficiency, quality, or safety. 

Many of the models of causation of injnries and illnesses... are operator models which are sophisticated versions of blame the worker safety approaches. 

Reynolds, in Back to the Future The Importance of Learning the ABCs of Behavioral Safety, discusses the need to first analyze the management controlled antecedents and consequences that actually drive those employee behaviors (p. 24). Many of the concerns expressed by highly capable safety professionals over the worker-focused behavior-based safety approach center on the fact that causal factors deriving from the work environment and work practices are ignored. Most behavior-safety practitioners do not recognize the need to examine the reasons—the antecedents, if you like — for the existence of hazards and risks. 

Obviously, this approach to behavioral safety does not focus on the worker and the observations of worker behavior that are the core of many other behavioral safety approaches. And, it emphasizes performance, overall. Those who have an interest in an imaginative approach to behavioral safety will want to read Pounds article, which describes in depth the elements outlined above. 

The modem safety approach is the plan-do-check-act methodology. 

Some of these safety approaches and innovations are not tried and tested interventions, but are based on the whim of some safety organizations and various psychology departments using outdated and inaccurate safety research. These approaches have launched a trend in the safety industry that is followed almost blindly. No one seems to question their validity or effectiveness. 

Additionally, the integral safety studies of typical plants (see Section 1-2), starting with the Rasmussen study, caused the technical experts to completely rethink the safety approach hitherto followed. Now the design engineers and operators were... 

The improvement of this situation calls for the use of present available knowledge on aU levels. Vietnam has proformd practical experience in the field of flood protection, however, the theoretical knowledge in the fields of dike design, reliability and safety approach, risk analysis, policy analysis, statistics in relation to boundary conditions and mathematical modeling is not up to date. Therefore, the transfer of this knowledge was strongly recommended (DWW/RWS, 1996 Vrijling et ah, 2000 Mai et ah, 2006). 

The Helicopter Safety Study 3 (HSS-3) is a joint industry effort by the main oil companies operating on the NCS. Main objectives of the study are to assess the risk level associated with offshore helicopter transportation, propose indicators to monitor safety, and identify safely measures for further improvement. The study will address risk through two complementary approaches a risk approach using risk influence modeling, and a safety approach focusing on resilience engineering. The project was established... 

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